As much as my wonder holds for the mindbogglingly large, I reserve some of that wonder for the infinitesimally small. For a while in childhood, I became obsessed with fractions of time, and just how small they could get.

I remember as a child receiving a Casio digital watch as a birthday present. I was absolutely delighted with it, and amazed at how they could get a watch and a stopwatch in the same device!

It wasn't long before I embarked on a game that many of my peers with digital watches, had played for some time. The game was simple, you simply had to start and stop your stopwatch as quickly as possible.

The aim was to try and get it to start and stop within one 1/hundredth of a second. When I finally got the clock to stop at 0.01, I was delighted, however I couldn't help wondering about what was beyond that time.

How Slow Can You Go?

In the hundredth of a second it took me to press my stopwatch button twice, a sound wave would have had the time to travel approximately 3.40 metres (10 feet), and a photon of light (in a vacuum) would travel around 3000 kilometres (1800 miles), roughly the distance from New York to the Central American city of Belmopan, Belize.

However we can measure much smaller amounts of time than that, let's start at a nanosecond. That is one billionth of a second, and as you know from my article Make Numbers Great Again, a billion is a huge number. To remind you, it would take 31.7 years if you were to try to count to a billion at the rate of one number per second.

In one billionth of a second, a beam of light (in a vacuum) only has time to travel just 12 inches (30 cm). Not much else will happen at that timescale, two photographs of a violent explosion taken a nanosecond apart will look identical.

Approaching Full Stop

Carrying on our merry journey down the rabbit hole to the origin of time, we stop briefly to marvel at the picosecond, one trillionth, or one millionth of one millionth of a second, or 0.000 000 000 001 seconds. A picosecond is to one second as one second is to 31,710 years.

It is amazing that we have actually managed to measure two distinct points that are just a picosecond apart, but on we go! Down and down, closer and closer to full stop.

Rewriting The 3 Second Rule

Now we pause at the femtosecond, one quadrillionth of a second. I stop here to mention that if you drop your food on a filthy floor, and manage to pick it up in less than 3 femtoseconds of it 'hitting'* the floor, then that would be fast enough to stop any of the filth on the floor getting on your tasty sandwich.

*At that timescale your food could not really have been deemed to have hit the floor in any meaningful sense.

The Briefest Moment

In 2015, we measured time in a scale called zeptoseconds, funnily enough, using an attosecond laser. In that experiment, scientists observed an electron leaving a Helium atom after being struck by a single photon of light.

The entire event took just 850 zeptoseconds(zs); to date it is the briefest interlude of time ever recorded, it is only enough time to allow light to travel the length of 10 hydrogen atom diameters.

Two universal pictures taken 1 zeptosecond apart, would look practically identical even on the subatomic scale.

The Pixel Of The Universe

So what is the smallest amount of time that there ever could be? Is there even such a limit? Indeed there is my friends! For anything to have said to have happened, the light from that event, must travel from it's origin to another point in space.

Therefore the smallest amount of time is measured by how long light would take to travel along the smallest possible distance in space, which is the Planck length.

OK prepare for mind blown in 3 .. 2 ...,

The size of an atom is 0.0000000001 metres

Compared to the size of the Plank length 0.000000000000000000000000000000000016

To put that into perspective if you owned a box of tiny little matches, each one measuring the Planck lengths; and then you laid them down end to end, at the rate of one per second. It would take you 10,000,000 times the age of our 14.9 billion year old universe, before you got to the size of an atom.

!

So the Plank length is to an atom, what the human body is to the universe . . .

What, I wonder, would it look like inside an atom . . . ?

Sources:
Planck length scale facts: https://newt.phys.unsw.edu.au/The Planck scale: relativity meets quantum mechanics meets gravity
Wiki: Orders of magnitude (time)
Wiki: Picosecond facts
New York distance calculatorDistance Counter (NYC)
Further reading:
Helium/photon experiment Smithsonian: Meet the Zeptosecond, the Smallest Slice of Time Yet Recorded

Watch: Is The Five Second Rule True? VSauce

Twin article:
Making Numbers Big Again

More Cryptogee Musings

I HOPE YOU'VE ENJOYED THIS MIND BENDING MUSE WITH ME, I LOOK FORWARD TO SEEING YOU NEXT TIME!

Cryptogee